1. Field of the Invention
The present invention relates, in general, to cutting inserts for high-efficiency cutting and, more particularly, to a cutting insert for high-efficiency cutting which has increased stiffness and thus makes it possible to stably conduct a cutting process despite the realization of rapid feed cutting, in which the number of cutting edges is increased, thus extending the lifetime of the cutting insert, and which can be applied to a milling operation and a turning operation, thus realizing a multi-functional structure and being economical, and can increase productivity when cutting and realize high-quality cutting.
2. Description of the Related Arts
Generally, cutting tools are used to cut iron, nonferrous workpieces, and nonmetallic workpieces. Typically, cutting tools are held by machines and cut workpieces to form them into desired shapes. Such a cutting tool includes a cutting insert, which has a cutting edge, and a cutter body, which supports the cutting insert.
Furthermore, according to a method of fixing a cutting insert to a cutter body, the cutting tools are classified into a brazing type cutting tool and an indexable type cutting tool. In the brazing type cutting tool, a cutting insert is permanently fixed to part of a cutter body by brazing. In the indexable type cutting tool, a cutting insert is removably fastened to a cutter body using a locking means, which is provided in the cutter body.
In the case of the indexable type cutting tool, because the cutting insert can be easily replaced with a new one when the lifetime of the cutting edge thereof expires, it can overcome the problem with the brazing type cutting tool, that is, the problem in which an expert must spend a long time grinding the cutting edge of the cutting insert after the lifetime of the cutting edge has been spent. Therefore, at present, indexable type cutting tools are widely used in the field of cutting tools.
Meanwhile, as methods of cutting a metallic workpiece using the cutting tool, there are two representative methods. First, there is a cutting method in which a workpiece, which is rotated, is brought into contact with the cutting edge of a cutting tool, which is stationary. Second, there is a cutting method, in which a tool having a cutting edge, that is, a cutting insert, is fixed to a machine using a tool holder, and, in this state, the cutting insert is rotated and is brought into contact with a workpiece, which is stationary, thus forming the workpiece into a desired shape. Turning is a representative example of the first cutting method, and milling is a representative example of the second cutting method.
Recently, in the cutting tool market, as part of the trend of pursuing high economic efficiency, high production efficiency and multi-functionality, various products to be used in turning machines and milling machines have been developed to improve economic efficiency and cutting quality and to realize high productivity by rapid feed cutting.
However, in the case of a conventional single-sided cutting insert, which is typically used in milling, the number of cutting edges to be used is limited due to the single-sided structure. Furthermore, the conventional single-sided cutting insert is disadvantageous in that, because a clearance angle is defined in the side surface thereof, the strength of the cutting insert is reduced, with the result that the cutting insert may be damaged by high-speed and rapid feed cutting.